37results about How to "Achieve white light emission" patented technology

The invention relates to a preparation method of a nitride-boride fluorescent powder material. The preparation method is characterized in that common metal salt or oxide is used as the raw material, a high-temperature solid-phase method is used for preparation, the preparation process of nitride fluorescent powder is simplified, and production cost is lowered. The expression of the nitride-boride fluorescent powder material is AM4-4x(BN2):xD, wherein A is one or more of Li, Na, K, Rb and Cs; M is one or more of Mg, Ca, Sr and Ba, and D is one or more of Mn<2+>, Ce<3+>, Pr<3+>, Nd<3+>, Pm<3+>, Sm<3+>, Sm<2+>, Eu<3+>, Eu<2+>, Tb<3+>, Dy<3+>, Ho<3+>, Er<3+>, Tm<3+>, Yb<3+> and Yb<2+>. The preparation method specifically includes: weighing the raw materials of A, M and D and boric acid according to stoichiometric ratio, adding appropriate amount of acetone into the raw materials, and sufficiently grinding to obtain a mixture; performing heat preservation on the mixture for 1-5 hours in an environment of 400-650 DEG C and under reduction atmosphere; grinding and evenly mixing obtained preliminary-combustion substance, and performing heat preservation on the mixture for 1-8 hours in an environment of 700-900 DEG C to obtain the nitride-boride fluorescent powder material. The preparation method has the advantages that the method using a solid-phase synthesizing method is low in synthesizing temperature, simple in preparation process, low in cost, safe, reliable, short in production cycle and suitable for large-scale industrial production, and the prepared fluorescent powder is excellent in light-emitting efficiency.

The invention provides a d-p heteronuclear bimetallic organic framework material capable of white light emission and a preparation method thereof; the molecular formula of the d-p heteronuclear bimetallic organic framework material is: {[Pb 2 Zn(L) 2 (H 2 O) 2 ]·NMP·H 2 O} n ; The present invention also relates to the preparation method of material. The invention is synthesized under hydrothermal conditions, has simple process, low cost and good repeatability. The Pb-Zn-based HMOF material prepared by the present invention can realize white light emission under the irradiation of an ultraviolet lamp, and has good chemical stability and thermal stability, and is an excellent new high-efficiency luminescent crystal material. The Pb-Zn-based HMOF material prepared by the present invention can realize white light emission under the irradiation of an ultraviolet lamp, and can be applied to light-emitting diodes, fluorescent immunoassays, optical fiber communications, photochemical sensing, and the like.

The invention discloses a green light luminescent material which comprises the material with the following chemical formula: a CaO. B Al2O3, c SiO2: x Tb, wherein the a is larger than and equal to 0.4 and is less than and equal to 2.5, the b is larger than or equal to 0.2 and is less than or equal to 1.5, the c=1.0, and the x is larger than or equal to 0.001 and is less than or equal to 0.8. The green light luminescent material has high luminous efficiency, good stability and high luminous intensity, can be used in 'UV-LED+red, green and blue three-base color fluorescent powder', and replaces the LED chip and is matched with the cerium-activated tombarthite garnet yellow fluorescent powder to send the white light. The preparation method of the green light luminescent material comprises the following steps of: adopting at least one oxide, carbonate and oxalate of Ca, Al2O3, SiO2 and Tb4O7 as raw materials, calcinating at high temperature under the reducing atmosphere, cooling to room temperature, and grinding to obtain the green light luminescent material. The preparation method of the green light luminescent material is simple in technology step, easy to control the technical conditions, easy to operate and low in cost.

The invention relates to the field of a semiconductor, and discloses an LED epitaxial structure. The LED epitaxial structure comprises a substrate, a nucleating layer, a non-doped GaN layer, an n type GaN layer and a porous SiN<x> layer on the n type GaN layer, and also comprises an n type GaN hexagonal-pyramid array formed in the holes of the porous SiN<x> layer, and quantum dots on the peak of the hexagonal pyramid, quantum lines on the six ridges and a multi-quantum-well layer on six semi-polar (10-11) crystal surfaces, and a p type GaN filling layer at the tail part; and the GaN hexagonal pyramid and the quantum dots / lines / well layer at different positions thereon form the three-dimensional core-shell structure. The structure is large in light emitting area and high in light extracting efficiency; in addition, due to influences of different In contents and polarization effects and other factors, the light emitting wavelengths of the quantum dots / lines / well structures are also different; through reasonable control, white light emission can be realized; in the preparation method of the GaN hexagonal pyramid array, substrate patterning is not needed, so that the technological process is simple; and meanwhile, the grown GaN crystals are high in quality, so that the luminous efficiency of the LED can be improved effectively.